One method to convert chemical reactant energy directly into useful work such as electricity uses electrochemical couples such as batteries and fuel cells. In this method, a substantial fraction of the reactant bond energies may be converted directly into electrical potential. However, the physical chemistry underlying these processes limits the rate of such conversion substantially. The result of the electrochemical conversion method is a power per mass and power per volume in a real device, such as a battery or fuel cell, that is at least an order of magnitude smaller than that of a mechanical engine.
Another method uses gas dynamic processes to convert chemical energy directly into a dynamic state exhibiting a population inversion. Stimulated emission extracts this energy from this reactants in the form of coherent radiation. However, the efficiency is substantially below that of electrochemical and mechanical methods, and the reactants and exhausts of this method are usually dangerous and incompatible with human safety considerations. Moreover, these devices cannot be efficiently miniaturized.
Therefore, it is highly desirable to have a compact method and system for chemical extracting energy efficiently without having to use harmful products and without producing hazardous byproducts in the process.
A recent surface sensor research has shown that during the adsorption event when chemical specie such as atoms or molecules adsorb on the surface of metal, hot charge carriers are emitted. “Hot” means with an energy several or many times that associated with the 0.026 electron volts (eV) of room temperature. The observed hot carriers showed energy in excess of the Schottky barrier of approximately 0.6 eV. Therefore, it is highly desirable to use energized specie to generate the hot carriers and/or collect the hot carriers.
Recent experimental and theoretical developments in surface science showed that gas molecules vibrating with an energy nearly sufficient to break their chemical bonds (quantum number of order 15) deposit nearly all this energy into a metal surface at the moment of contact, and bounce off the surface with much less vibrational energy (quantum number of order 5). That the molecule should loose many quanta all at once in the period of order 100 femto-seconds was unexpected. This explanation is called an “electron jump,” where an electron from the metal surface jumps on to the energetically vibrating molecule just as the molecule approaches the surface. The electron then jumps back into the metal, taking with it most of the vibrational energy.
Implicit in this electron jump observation is that the bond energy transfers to an electron. There are few if any available mechanical modes to accept the energy because the Debye frequency of the metal substrates is at least 1 to 2 orders of magnitude lower than the frequency of the excitations. Electrons may accept the energy because the metal surface has a high density of electron states available to accept the energy.
The electron jump research implies, but did not measure, that an electron carries away a majority of the energy contained in the energized bond. The electron jump research does not attempt to measure or detect such a hot electron. Other observations of surface effects, theory and the surface sensor research strongly implicate that an electron takes the energy. Observations strongly support the theory of prompt, multi-quantum energy transfer to an electron from a vibrationally excited chemical specie in brief contact (of order 0.1 picoseconds) with the substrate metal surface. Accordingly, it is desirable to have a method and device to convert the chemical energy of a reaction of fuel and oxidizer on a catalyst surface into electrical energy. It is also desirable to use fuel and oxidizer to create the highly energetic specie directly in contact with a catalyst surface.